The opposition tried but failed to pass a motion calling for the sacking on Thursday morning, with shadow attorney-general Mark Dreyfus accusing Mr Joyce of the “clearest possible breach” of the ministerial code of conduct, which says ministers should not attempt to encourage personal gifts.

Mr Joyce concedes he was given free access to a property in Armidale by wealthy businessman and political donor Greg Maguire, who he describes as a “mate”, but denies any wrongdoing.

He moved into the house with his former staffer Vikki Campion, who is now his partner and is expecting a child. The couple’s affair and the breakdown of Mr Joyce’s marriage was revealed in national media last week.

Mr Joyce has acknowledged the property in the “gifts” section of his pecuniary interest register, in an update he submitted after his by-election victory in New England last December. The listing does not put a value on the gift and simply reads: “Post election residual of six-month tenancy on Armidale premises”.

The Nationals leader said the offer came after he was ejected from parliament by the High Court, so he was not a minister at the time. Mr Joyce also said the gift was offered, not solicited, so would not be covered by the code.

Poll shows New England voters split on Joyce affair

Voters in Barnaby Joyce’s electorate of New England are split almost 50-50 on whether the Nationals leader should resign in the wake of the scandal, according to a new opinion poll commissioned by Fairfax Media.

The poll found 45.3 percent of voters in the northern NSW seat wanted Mr Joyce to remain as party leader and deputy prime minister.

Another 26.7 percent said he should resign from his leadership positions and move to the backbench, while a further 20.5 percent said he should quit parliament completely. 7.5 percent were undecided.

Arriving at Parliament House on Thursday, a defiant Barnaby Joyce said he was confident he would survive as Nationals leader.

“I’ve got the support of my party room,” Mr Joyce told reporters as he entered the building. “We’re back into the business, working hard, doing what we’re supposed to.”

Along with the questions over the free Armidale rental, Labor is pushing the government to release details of any taxpayer-funded trips taken by deputy prime minister Barnaby Joyce and Vikki Campion while she was working as a Nationals staffer.

On Wednesday, Labor senator Kimberley Kitching tabled a notice of motion calling for the details of Mr Joyce and Ms Campion’s “special purpose travel” and any international flights.

Opposition leader Bill Shorten said Mr Joyce’s position had become “untenable”, echoing calls from other Labor MPs for the deputy PM to resign.

“Australians are not interested in Barnaby Joyce’s private life, that’s his,” Mr Shorten said. “But there are conflicts of interest coming out daily which are being revealed. The prime minister has a ministerial code of conduct which, if he doesnt uphold, is not worth the paper it’s written on.”

The questioning is likely to continue in Question Time on Thursday afternoon. It is the last sitting day of parliament before Mr Joyce is due to take over as acting prime minister, while Malcolm Turnbull is abroad in the United States next week.

Mr Joyce has been under intense political pressure and media scrutiny since his affair with now-pregnant Ms Campion was revealed.

Nationals back Joyce to keep leadership, for now

The pressure on Mr Joyce has forced his colleagues to declare their support for his ongoing leadership.

A number of his fellow Nationals have jumped to their leader’s defence. MP David Littleproud said “of course” Mr Joyce retained the support of the majority of members. “He’s done an amazing job for regional and rural Australia,” he said.

Nationals whip Michelle Landry said she believed Mr Joyce still had the numbers and would “remain our leader”.

Their defences came after Nationals MP Ken O’Dowd said a delegation of his colleagues planned to visit Mr Joyce to “tell him where the party stands” on his leadership.

“He’ll probably need the advice and someone needs to tell him where the party stands at this stage,” he told reporters on Wednesday morning.

Mr O’Dowd said there were plenty of capable candidates if the scandal triggered a leadership spill.

He has previously suggested he may put his hand up for the leadership himself.

“We would find a good leader, I feel sure about that,” he said.

Joyce denies any breach of ministerial rules

The ministerial code of conduct says partners and close relatives of ministers are not allowed to be given jobs within the minister’s office, or with other members of the executive, without the express permission of the prime minister.

Ms Campion was moved from Mr Joyce’s office into the employment of Nationals colleague Matt Canavan and then to the office of Damien Drum.

Mr Turnbull’s office said the prime minister had never needed to grant permission because Ms Campion was not Mr Joyce’s “partner” at the time.